1. Field of the Invention
The present invention is related to presentation systems using a display computer, a computer-controlled image projector, and a projection screen and, more particularly, to an interactive display presentation system in which control is accomplished by moving a laser pointer beam across the projection screen in a pre- established spatial pattern.
2. Description of the Related Art
Charts, text, and various graphical images are commonly presented to an audience in meetings and in classrooms by optically projecting these images onto a projection screen or a wall. An LCD (liquid crystal display) projector is commonly used as the image source, where the charts, text, and graphical images are electronically generated by a display computer, such as a personal computer (PC) or a laptop computer, which typically execute presentation-generating software, such as Microsoft PowerPoint(copyright). In such display systems, the PC provides video outputs such as standard VGA, Super VGA, or XGA. These LCD/PC projection display systems are becoming more popular than the traditional overhead projector and transparencies which they replace.
Whether the operator is standing at a lectern, or is moving about before the audience, he has little direct control over the image being displayed upon the projection screen when using a conventional LCD/PC projection display system. A conventional system requires the operator to return to the display computer, or to have an assistant seated at the computer, so as to provide control for the presentation. At the display computer, either the presenter or the assistant controls the displayed image by means of keystrokes or by xe2x80x9cmouse commandsxe2x80x9d with a cursor in the appropriate area of the computer monitor display screen. The actions of the operator moving to the display computer, or communicating with the assistant, detracts from a natural progression and flow of the presentation. It can be appreciated that the operator develops a closer rapport with the audience the more he is able to interactively control the display presentation or to modify the image appearing on the projection screen without repeatedly redirecting his attention from the screen to an assistant or moving to the display computer.
For example, with the control system disclosed in U.S. Pat. No. 5,782,548, issued to Miyashita, the operator uses a remote control device to wirelessly transmit control signals to a projector sensor. This system requires the operator to turn away from his audience and from the projection screen and to direct his attention to the projector via the remote control device when he wishes to change the presentation image on the screen. Moreover, although the operator acquires some mobility by means of the remote control device, the mobility is limited as he must stay in range of the projector sensor.
It is also known in the art to use a laser pointer projecting a laser spot onto to a region of the presentation image. Such systems typically require multiple steps or actions to be taken in exercising control over the presentation, and this serves to inhibit a natural progression and flow of presentation. In way of example, U.S. Pat. No. 5,682,181, issued to Nguyen et al., discloses a system in which the operator calls up a drop-down menu before a particular function, such as draw mode, page up, etc., can be selected. U.S. Pat. No. 5,502,459, issued to Marshall et al., discloses a method of effecting a mouse double-click in which the user must first activate, then deactivate, then activate again, and again deactivate the laser pointer while maintaining the projected laser spot within an imaginary rectangular area on the presentation image. Other systems require that additional components be used with the conventional LCD/PC projection display systems. U.S. Pat. No. 5,504,501, for example, provides remote control by means of a laser pointer, but requires the use of an optical filter to isolate the laser spot from the surrounding presentation image.
The prior art does not appear to have provided an interactive display presentation system in which the operator is able to control the presentation, such as by providing mouse commands, while retaining a high degree of interaction with the audience. It is therefore an object of the present invention to provide such a presentation system which overcomes these and other limitations of conventional display presentation systems.
It is another object of the present invention to provide such a system in which mouse commands and other presentation functions, such as advancing to a subsequent image, underlining, zooming in, or highlighting, are executed by simply gesturing with a laser pointer. Other objects of the invention will be obvious, in part, and, in part, will become apparent when reading the detailed description to follow.
The present invention provides an interactive presentation control system in which a presenter controls the presentation by projecting pre-established spatial patterns onto a projection screen by means of a laser spot emitted by a laser pointer. The pre-established spatial patterns are acquired and interpreted by the control system which subsequently issues display commands to a projector. During the presentation, a display computer generates on its local display a bitmap corresponding to the presentation. This bitmap is then transmitted to the LCD projector and the bitmap is then projected onto the screen. The display of the presentation is controlled by the monitoring of the laser spots that are also projected onto the screen. Laser spot control is achieved through a control system. The control system comprises a digital camera which acquires successive images of the laser spot and a control module comprising a processing section which analyzes the positions of the laser spot across the presentation images. When the processing section matches the successive laser spot positions with a pre-established spatial pattern, the corresponding display command is issued. The display command may be transmitted to the display computer which responds by an action such as advancing to the next electronic image, or the display command may perform a function within the control module, such as highlighting text or zooming in on a portion of the presentation image.